As she mounts a challenge to Republican Sen. Scott Brown of Massachusetts, former Harvard Law school professor and consumer advocate Elizabeth Warren has tried to put her controversial days in Washington behind her – but it hasn’t been easy.

Politico reported on Thursday that Warren, an unrelenting advocate of transparency in government, has been less than forthcoming about how the Congressional Oversight Panel she chaired for two years spent more than $10 million of taxpayer’s dollars in overseeing the government’s Troubled Assets Relief Program. Warren has yet to break down how much she received in total salary and how much the panel spent on travel expenses, meals and consultants, according to the report.

Moreover, an August video of Warren on the campaign trail that is ricocheting around the Internet shows her rebutting Republican claims that raising taxes on the wealth is tantamount to “class warfare,” declaring that “there is nobody in this country who got rich on his own. Nobody.”

Warren, a champion of liberals and progressives, essentially rejected the idea that it is possible for Americans to become wealthy without help from others or the government. Republicans have already branded Warren as a liberal academic from Cambridge whose Harvard ties put her out of touch with working families, conservatives, and independents who believe Americans can get ahead on their own.

GOP critics have also mocked her as an outsider whose roots are in Oklahoma, where she grew up, and not Massachusetts. Warren has lived in Massachusetts for nearly two decades and said what’s most important is what’s in a candidate’s heart. Warren says she is running because “middle-class families have been chipped at, hacked at, squeezed, and hammered for a generation now, and I don’t think Washington gets it.”

Warren, the former head of a congressional TARP oversight committee and chief architect of a new Consumer Financial Protection Bureau, spent months fending off nasty attacks from Republicans and business leaders, who claimed she was anti-business and attempting to amass unprecedented regulatory power for herself and the new agency.

When President Obama decided to defuse the controversy and nominate Richard Cordray, a former Ohio attorney general, to head the consumer protection agency, Warren decamped for Boston and launched her bid for the Democratic senatorial nomination on Sept. 14.

Since then, the 62-year-old academic has vigorously campaigned to raise her recognition level and soften her image by greeting Massachusetts commuters at subway stops, Dunkin’ Donuts shops and suburban diners.

“There’s been a lot of very powerful interests who have tried to shut me down, squeeze me, push me sideways, and so far it just hasn’t worked,” Warren said. “I’m willing to throw my body in front of a bus to try to stop bad ideas that are going to be harmful to the middle class.”

The Progressive Change Campaign Committee, a liberal group, has raised more than $200,000 for Warren's campaign and has been actively helping her to fundraise and organize.

But she is also looking to the financial community to raise money. An email from Cravath, Swain & Moore Partner Richard Levin, who heads their restructuring practice to banking colleagues endorses Warren as “a thoughtful, unselfish, rational advocate for the economic interests of the middle class…She isn’t anti-bank. Rather, based on her extensive work studying the consumer financial system, she understands the need for rational regulation to correct inadequacies and simplify the market in consumer finance.”

Warren was heavily courted by Democrats hoping to win back the seat long held by Sen. Edward Kennedy, who died in 2009 after a long battle with brain cancer. Democrats also are trying to hold on to their narrow Senate majority by ousting Brown. According to a new poll out Tuesday from Public Policy Polling, Warren is already narrowly leading Brown, 46 percent to 44 percent.

Warren said she knows she has to make her case in a crowded primary if she wants a chance to challenge Brown. Some Democrats, including Boston Mayor Thomas Menino, have voiced skepticism about how strong a candidate she will be, given her lack of political experience.

University of Virginia political scientist Larry Sabato believes Warren faces an uphill battle to unseat Brown, and that “this race is Brown’s to lose.”

“Out of 33 Senate races, it is literally the best chance the Democrats have to take over a Republican seat,” Sabato told The Fiscal Times. “And that tells you how bad off the Senate Democrats are in 2012.” Despite Warren's lead in the poll, Sabato said, Brown has turned into the kind of moderate Republican that Massachusetts has been willing to elect in the past. He has a positive profile and broad favorability, plus tons of money.

“His real opponent is Barack Obama--or rather Obama's coattail,” Sabato says. “Warren guarantees that Brown will have all the campaign cash he needs to go after her hard. He'll use every controversial statement she's ever made in a TV ad at some point. Brown's job is to portray her as another Martha Coakley [who lost to Brown in a special election], only loony-left, a Harvard elitist, and anti-business. On the other hand, the left has adopted Warren, and they will make sure she is also well funded, with an enthusiastic grassroots volunteer operation. Warren will run as Obama Warren, not Elizabeth Warren.”

Throughout her career, Warren has rarely minced her words. The former Harvard law professor has portrayed banks and brokers as little more than crooks and con artists and berated federal regulators who “played the role of lookout at a bank robbery.” As head of the congressional oversight panel on the federal bailout of the nation’s banks, Warren has publicly lectured Treasury Secretary Tim Geithner and other senior officials for their handling of the financial crisis, and once declared that she and Geithner don’t “see the world the same way.”

In a 337-page report released in June 2010 on American International Group by her five-member Congressional Oversight Panel , Warren charged that the Treasury and Federal Reserve squandered opportunities to get a better deal for taxpayers in the bailout of AIG.

Dan Pedrotty, an AFL-CIO official who helped marshal support for the sweeping financial reform, said last year that Warren was “far and away the strongest candidate" to lead the Consumer Financial Protection Bureau and that the creation of the agency "was probably one of two or three most important aspects of the new Wall Street reform bill.”

But Warren’s critics argued that her aggressive advocacy and stinging rhetoric made her the wrong choice to head an agency that will have to mediate between conflicting industry and consumer advocacy interests as it writes and enforces a raft of new regulations.

“Warren adheres to behavioral economics theory where basically consumers are [considered] misinformed, irrational, and can’t really make decisions in a clear-eyed way, so the only way to really protect the consumers is to make sure the government is in there rationing credit cards that are available to them,” said an industry group expert who declined to be identified in discussing her group’s views on Warren.

Washington Editor and D.C. Bureau Chief Eric Pianin is a veteran journalist who has covered the federal government, congressional budget and tax issues, and national politics. He spent over 25 years at The Washington Post.